Ractopamine as a metabolic modifier feed additive for finishing pigs: a review

The β-adrenergic agonist ractopamine is increasingly used in the swine industry due to higher consumer demand for leaner pork products. Redirecting nutrients to favor leanness rather than fat deposition, ractopamine improves growth and carcass traits of finishing pigs. However, the impact of this agonist on pork quality is not clearly defined. Understanding the biological effects of dietary ractopamine dose, treatment period, lysine levels, and the lysine to metabolizable energy ratio will help pork producers achieve improvements in animal performance, carcass leanness, and economic efficiency in swine production systems

Ractopamine, chromium-methionine and their combinations as metabolism modifier feed additives of growing and finishing pigs

Objetivou-se neste estudo avaliar o efeito da adição de ractopamina, cromo-metionina e suas combinações em dietas para suínos em crescimento e terminação sobre o desempenho, as características de carcaça e a qualidade da carne. Sessenta e quatro suínos da linhagem Topigs, com peso inicial de 26,56 ± 3,11 kg, foram distribuídos em delineamento experimental de blocos casualizados em esquema fatorial 2 x 2, com dois níveis de ractopamina (0 e 5 ppm) e dois níveis de cromo-metionina (0 e 400 ppb), totalizando quatro dietas com oito repetições (blocos) por dieta. Em cada uma das três fases, crescimento 1 (de 26,56 kg aos 50,51 kg), crescimento 2 (de 50,51 kg aos 70,32 kg) e terminação (de 70,32 kg aos 114,80 kg), os animais receberam rações fareladas e água à vontade. Ao atingirem o peso vivo de 114,80 ± 4,98 kg, os animais foram abatidos e as carcaças avaliadas quanto ao rendimento de carcaça fria, ao comprimento de carcaça, à espessura de toucinho, à área de olho-de-lombo e à relação gordura:carne. Amostras do músculo longissimus dorsi foram retiradas para mensurações de cor, pH final e perda de peso por gotejamento. A suplementação de ractopamina melhorou a conversão alimentar, o rendimento de carcaça fria, a área de olho-de-lombo, a relação gordura:carne e a perda de peso por gotejamento e reduziu os teores de vermelho e amarelo da carne. O cromo-metionina, embora tenha ocasionado redução no consumo diário de ração, não altera as características de desempenho e de carcaça nem a qualidade da carne dos suínos. A suplementação de ractopamina associada a cromo-metionina não afeta o desempenho nem as características de carcaça e qualidade da carne dos animais.The purpose of this study was to evaluate the effect of ractopamine and chromium-methionine additions and their combinations in diets for growing and finishing swines on performance, carcass traits and meat quality. Sixty-four Topigs line swines at 26.56 ± 3.11 kg initial body weight were distributed in a randomized block experimental design in a 2 x 2 factorial scheme with two levels of ractopamine (0 and 5 ppm) and two levels of chromium-methionine (0 and 400 ppb), totaling four diets with eight replications (blocks) per diet. In each one of the three following phases, growing 1 (from 26.56 kg to 50.51 kg), growing 2 (from 50.51 kg to 70.32 kg) and finishing (from 70.32 kg to 114.80 kg), meal rations and water were given ad libitum to animals.When pigs reached 114.80 ± 4.98 kg body weight, they were slaughtered and carcasses were evaluated regarded to cold carcass yield, carcass length, backfat thickness, loin eye area and fat:meat ratio. Samples of longissimus dorsi muscle were taken to measure colour, final pH and drip loss. Supplementation of ractopamine improved feed conversion, cold carcass yield, loin eye area, fat:meat ratio and drip loss, and it reduced redness and yellowness components of meat. Although chromium-methionine decreased daily feed intake, it does not affect the performance and carcass traits neither meat quality of swines. Supplementation of ractopamine combined to chromium-methionine do not affect carcass traits and meat quality of animals

Dietary Fat Content and Fiber Type Modulate Hind Gut Microbial Community and Metabolic Markers in the Pig

Obesity leads to changes in the gut microbial community which contribute to the metabolic dysregulation in obesity. Dietary fat and fiber affect the caloric density of foods. The impact of dietary fat content and fiber type on the microbial community in the hind gut is unknown. Effect of dietary fat level and fiber type on hindgut microbiota and volatile fatty acid (VFA) profiles was investigated. Expression of metabolic marker genes in the gut, adipose tissue and liver was determined. A 2×2 experiment was conducted in pigs fed at two dietary fat levels (5% or 17.5% swine grease) and two fiber types (4% inulin, fermentable fructo-oligosaccharide or 4% solka floc, non-fermentable cellulose). High fat diets (HFD) resulted in a higher (

Effect of dietary soybean oil inclusion on liver-related transcription factors in a pig model for metabolic diseases.

Dietary fatty acids (FA) are components of the lipids, which contribute to membrane structure, energy input, and biological functions related to cellular signaling and transcriptome regulation. However, the consumers still associate dietary FA with fat deposition and increased occurrence of metabolic diseases such as obesity and atherosclerosis. Previous studies already demonstrated that some fatty acids are linked with inflammatory response, preventing metabolic diseases. To better understand the role of dietary FA on metabolic diseases, for the first time, a study to identify key transcription factors (TF) involved in lipid metabolism and inflammatory response by transcriptome analysis from liver samples of animal models was performed. The key TF were identified by functional enrichment analysis from the list of differentially expressed genes identified in liver samples between 35 pigs fed with 1.5% or 3.0% soybean oil. The functional enrichment analysis detected TF linked to lipid homeostasis and inflammatory response, such as RXRA, EGFR, and SREBP2 precursor. These findings demonstrated that key TF related to lipid metabolism could be modulated by dietary inclusion of soybean oil. It could contribute to nutrigenomics research field that aims to elucidate dietary interventions in animal and human health, as well as to drive food technology and science

Production responses and gene expression induced by ractopamine feeding duration for finishing pigs

O agonista beta-adrenérgico ractopamina (RAC) modifica a composição da carcaça suína por aumentar a massa muscular e reduzir a deposição de gordura. O objetivo neste estudo foi avaliar os efeitos do tempo de fornecimento de RAC sobre o desempenho, concentração de ureia plasmática (CUP), características de carcaça e expressão gênica dos receptores beta- adrenérgicos (beta-AR) e das isoformas da cadeia pesada de miosina (MyHC) em suínos em terminação. Oitenta suínos, machos castrados (PV inicial = 69,42 ± 1,24 kg), foram utilizados em um experimento em blocos completos casualizados com cinco tratamentos, oito repetições por tratamento e dois animais por unidade experimental (baia). Os tratamentos consistiram de rações sem RAC (controle) ou com 10 ppm de RAC fornecidas por 7, 14, 21 ou 28 dias préabate. O PV individual e o consumo de ração por baia foram obtidos para determinar o ganho diário de peso (GDP), o consumo diário de ração (CDR) e a conversão alimentar (CA). Amostras de sangue foram coletadas para determinação da CUP. No final do experimento, os animais (PV final = 102,46 ± 1,44 kg) foram abatidos e amostras de pelos e do músculo Longissimus dorsi coletadas. As carcaças foram avaliadas 24 horas post-mortem. As amostras de pelos foram utilizadas para detecção da mutação no gene do receptor de rianodina do tipo 1 (RYR1). A expressão gênica dos beta-AR (subtipos beta1 e beta2) e das isoformas MyHC (I, IIa, IIx/d e IIb) foi quantificada nas amostras de músculo. As análises estatísticas foram realizadas apenas com os animais homozigotos dominantes para a mutação no gene do RYR1. O aumento no período de fornecimento de RAC não afetou (P > 0,05) o PV final, o GDP e o CDR, porém resultou em melhora linear (P 0,05) sobre a expressão gênica dos beta1-AR e das isoformas MyHC IIa e MyHC IIx/d, porém o aumento no período de fornecimento de RAC tendeu a reduzir linearmente (P = 0,08) a expressão gênica dos beta2-AR. Embora os níveis de RNAm da isoforma MyHC I tenham sido reduzidos linearmente (P 0.05) final BW, ADG, and ADFI, but resulted in a linear improvement (P 0.05) were detected for beta1-AR and for isoforms of MyHC IIa and MyHC IIx/d gene expression, but increasing RAC feeding period tended to linearly decrease (P = 0.08) beta2-AR gene expression. Even though mRNA levels of MyHC I isoform decreased linearly (P < 0.01), gene expression of MyHC IIb isoform increased linearly (P < 0.01) as RAC treatment duration increased. Therefore, greater growth and carcass responses occurred when RAC was fed for 21 and 28 days, respectively. Furthermore, the agonist altered the MyHC gene expression and the RAC action may be related to the beta2-AR population

Ractopamine, chromium-methionine and their combinations as metabolism modifier feed additives of growing and finishing pigs

O objetivo deste trabalho foi avaliar o efeito da ractopamina, cromo-metionina e suas combinações nas dietas de suínos em crescimento e terminação sobre o desempenho, as características de carcaça e a qualidade da carne. Sessenta e quatro suínos da linhagem Topigs, com peso médio inicial de 26,56 ± 3,11 kg, foram distribuídos em um delineamento experimental de blocos casualizados em esquema fatorial 2 x 2, sendo dois níveis de ractopamina (0 e 5 ppm) e dois níveis de cromo-metionina (0 e 400 ppb), perfazendo quatro tratamentos. Os tratamentos foram: C controle: dieta basal constituída por milho e farelo de soja; Rac ractopamina: dieta basal com a inclusão de 5 ppm de ractopamina dos 70,32 aos 114,80 kg de PV; Cr-Met cromometionina: dieta basal com a inclusão de 400 ppb de cromo-metionina dos 26,56 aos 114,80 kg de PV; Rac + Cr-Met ractopamina + cromo-metionina: dieta basal com a inclusão de 400 ppb de cromo-metionina dos 26,56 aos 114,80 kg de PV e 5 ppm de ractopamina dos 70,32 aos 114,80 kg de PV. Foram utilizados oito repetições (blocos) por tratamento e dois animais por unidade experimental (um macho castrado e uma fêmea). O período experimental foi dividido em três fases, de acordo com o peso dos animais: crescimento I: 26,56 aos 50,51 kg de PV; crescimento II: 50,51 aos 70,32 kg de PV e a terminação: 70,32 aos 114,80 kg de PV. Ao atingirem o peso vivo médio de 114,80 ± 4,98 kg, os animais foram submetidos a jejum sólido de 24 horas e, posteriormente, encaminhados ao abate. As meias-carcaças foram resfriadas por cerca de 24 horas e avaliadas para o rendimento de carcaça fria, comprimento de carcaça, espessura de toucinho, área de olho-de-lombo e relação gordura:carne. Amostras do músculo Longissimus dorsi de cada animal, foram coletadas 24 horas post mortem para as mensurações da cor, pH e perda de peso por gotejamento da carne. A suplementação de ractopamina melhorou a conversão alimentar (P=0,05) e algumas características de carcaça [rendimento de carcaça fria (P=0,05), área de olho-de-lombo (P0,05). Além disso, a adição de ractopamina na dieta dos suínos acarretou diminuição na perda de peso por gotejamento (P0,05), nem as características de carcaça (P>0,05) e a qualidade da carne (P>0,05) dos suínos. A suplementação associada de ractopamina com cromo-metionina não afetou o desempenho (P>0,05), as características de carcaça (P>0,05) e, tampouco, e qualidade da carne dos animais (P>0,05). Portanto, o presente estudo mostrou que apenas a inclusão de ractopamina na dieta contribuiu para a melhoria do desempenho, características de carcaça e até mesmo da qualidade da carne dos suínos.The purpose of this study was to evaluate the effect of ractopamine, chromium-methionine and their combinations in growing and finishing diets on performance, carcass traits and meat quality of pigs. Sixty-four pigs of Topigs genetic with 26.56 ± 3.11 kg initial live weight were used in a randomized complete block design experiment, in a 2 x 2 factorial arrangement [two ractopamine levels (0 and 5 ppm) and two chromium-methionine levels (0 and 400 ppb)], resulting four treatments. The treatments were: C control: basal diet with corn and soybean meal; Rac ractopamine: basal diet with the inclusion of 5 ppm de ractopamine dos 70.32 to 114.80 kg; Cr-Met chromium-methionine: basal diet with the inclusion of 400 ppb of chromium-methionine dos 26,56 to 114,80 kg; Rac + Cr-Met ractopamine + chromiummethionine: basal diet with the inclusion of 400 ppb of chromium-methionine dos 26,56 to 114,80 kg and 5 ppm of ractopamine dos 70.32 to 114.80 kg. Eight replications (blocks) per treatment and two animals per experimental unit (one barrow and one gilt) were used. The experimental period was divided in three phases according to average live weight of animals: growing I: 26.56 to 50.51 kg BW, growing II: 50.51 to 70.32 kg BW and finishing: 70.32 to 114.80 kg BW. When pigs reached 114.80 ± 4.98 kg BW, a 24-hour-fasting period was given to animals before slaughter. Pig carcasses were stored for 24 hours in cold camera and then data of cold carcass yield, carcass length, backfat thickness, loin eye area and fat area/loin eye area ratio were registered. Samples of Longissimus dorsi of each animal were taken 24 hours postmortem to determine colour, pH and drip loss of meat. Ractopamine improved feed conversion (P=0.05) and some carcass traits [cold carcass yield (P=0.05), loin eye area (P0.05)]. Ractopamine reduced water drip loss (P0.05) and meat quality (P>0.05) of pigs. Combination of ractopamine and chromium-methionine did not affect performance (P>0.05), carcass traits (P>0.05) and meat quality (P>0.05) of animal. Therefore, this study showed that only ractopamine can enhance performance, carcass traits and some meat quality traits of pigs

Rice oil as a soybean oil replacement in weanling pig diets

The motivation for including oils in the diets of weanling pigs is to increase dietary energy density to meet the pigs' energy requirements. The purpose of this study was to determine the digestible and metabolizable energy values of semi-refined rice oil (RO) and refined soybean oil (SO) for weanling pigs (Experiment 1), as well as to evaluate how replacing SO with RO in weanling pig diets affects performance, intestinal histology, organ morphometry and the occurrence of diarrhea (Experiment 2). In Experiment 1,21 barrows, averaging 19.63 +/- 0.37 kg body weight (BW), were used in a randomized complete block design experiment, with seven replications per treatment and one pig per experimental unit (metabolism cage). The treatments consisted of a reference diet and two test diets. The test diets were obtained by using 90% of the reference diet and 10% of RO or SO. The experimental period consisted of a 7 days adaptation period, followed by a 5 days collection period of feces and urine. The values of the apparent digestible energy, apparent metabolizable energy and N-corrected apparent metabolizable energy of the oils were, respectively, 26.24, 25.78 and 26.01 MJ kg(-1) for RO and 31.74, 31.35 and 31.51 MJ kg(-1) for SO. In Experiment 2, 120 weaned pigs, castrated males and females, averaging 6.74 +/- 0.42 kg BW, were used in a randomized complete block design experiment, with eight replications per treatment and three pigs per experimental unit (pen) to evaluate the effects of five replacement levels of SO with RO in isonutritive weanling pig diets. The treatments were as follows: 4:0 basal diet with 4% of SO; 3:1 basal diet with 3% of SO and 1% of RO; 2:2 basal diet with 2% of SO and 2% of RO; 1:3 basal diet with 1% of SO and 3% of RO; and 0:4 basal diet with 4% of RO. No effects of the replacement levels were observed in the weanling pigs' performance, organ morphometry or in their occurrence of diarrhea. However, a quadratic effect on the villus width and a cubic effect on the villus height:crypt depth ratio were observed in the duodenum. Therefore, if the determined values of energy are used in the feed formulation, refined soybean oil can be replaced with semi-refined rice oil in weanling pig diets without affecting their growth performance. (C) 2011 Elsevier B.V. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

Utilização de glicerol na dieta de suínos em crescimento e terminação Use of glycerol in growing and finishing pig diets

Objetivou-se avaliar três níveis de utilização de glicerol (0, 3, 6 e 9%), um subproduto da produção de biodiesel, na dieta de suínos em crescimento e terminação sobre o desempenho, as características de carcaça e a qualidade da carne desses animais. Foram utilizados 64 animais Topigs com peso inicial de 33,27 ± 4,66 kg, distribuídos em 32 baias de acordo com o peso inicial, em um delineamento em blocos casualizados com oito repetições (blocos) por nível de glicerol. Em cada uma das três fases - crescimento 1 (33,27 a 65,00 kg), crescimento 2 (65,00 a 85,00 kg) e terminação (85,00 a 99,97 kg) -, os animais receberam rações isonutritivas e água à vontade. Ao atingirem o peso vivo médio de 99,97 ± 1,92 kg, os animais foram abatidos e as carcaças avaliadas quanto ao rendimento de carcaça quente, ao comprimento de carcaça, à espessura de toucinho, à área de olho-de-lombo e quanto à relação gordura/carne. Amostras do músculo longissimus dorsi foram retiradas para medição do pH, da cor e da perda de água por gotejamento. A adição de glicerol na dieta promoveu redução apenas no ganho diário de peso durante os períodos de crescimento 1 e 2. De modo geral, o glicerol pode ser utilizado como ingrediente energético em rações para suínos em crescimento e terminação, pois em níveis de até 9%, não influencia o desempenho, as características de carcaça e a qualidade da carne.<br>The purpose of this work was to evaluate three levels of use of glycerol (0, 3, 6 and 9%) a byproduct of biodiesel production, in the diets of growing and finishing swines on performance, on carcass traits and on meat quality. A total of sixty-four Topigs pigs with 33.27 ± 4.66 kg initial body weight were distributed in 32 pens accordingly to the initial weight in a complete random block design with eight replicates (blocks) per level of glycerol. In each of the three phases: growth 1 (33.27 to 65.00 kg), growth 2 (65.00 to 85.00 kg) and finishing (85.00 to 99.97 kg), the animals were fed isonutritional rations and water ad libitum. When the animals reached 99.97 ± 1.92 kg body weight, they were slaughtered and the following carcass traits were evaluated: hot carcass yield, carcass length, backfat thickness, loin eye area and fat/meat ratio. Samples of longissimus dorsi were taken for pH measurement, color and water drip loss. The addition of glycerol into the diet reduced only the daily weight gain during growth periods 1 and 2. Generally, glycerol can be used as energetic ingredient in diets for growing and finishing pigs up to 9% with no effect on performance, carcass quality and meat quality

Desempenho e saúde intestinal de leitões recém-desmamados suplementados com nucleotídeos

Previous studies reported benefits to growth performance, intestinal histology and reduced diarrhea for pigs supplemented with nucleotide additive as a replacement to antimicrobial growth promoters. The purpose of this study was to evaluate the effects of nucleotide levels on performance, occurrence of diarrhea, relative weight of organs, intestinal histology, and intestinal microbiota of weanling pigs. One hundred and sixty 21-d weaned pigs (6.43 ± 0.71 kg BW) were used in a randomized complete block design experiment with five treatments, eight replications per treatment and four animals per pen (experimental unit). The treatments were basal diet with 120 ppm of chloro-hydroxyquinoline (antimicrobial), and basal diet with 0 (control), 100, 150, or 200 ppm of nucleotides. The average daily gain (ADG), average daily feed intake (ADFI), gain to feed ratio (G:F), and occurrence of diarrhea were calculated from day 1 to 14, day 14 to 34, and day 1 to 34 of the experiment. A day after the end of the experiment, one animal from each pen was slaughtered to evaluate the relative weight of organs, intestinal histology, and intestinal microbiota. From day 1-14 and day 14-34 of the experiment, performance was not affected by the treatments. For the total experimental period (day 1-34), increasing the dietary concentrations of nucleotides linearly improved the final body weight and average daily gain. Salmonella spp. was detected only in the control treatment, without affecting the other microorganisms. Pigs fed with antibiotic had a lower occurrence of diarrhea from day 1-14 compared to pigs fed with nucleotide treatments. Although increasing the occurrence of diarrhea in the first 14 days, dietary nucleotides added up to 200 ppm, improve the final body weight and average daily gain at 34 days post weaning. Nucleotides and antimicrobial not shown beneficial effects on organ weights, and intestinal histology of nursery pig, however, are able to decrease the population of Salmonella spp. at small intestine.Benefícios ao desempenho zotécnico, histologia intestinal e menor incidencia de diarreia têm sido observados em suínos suplementados com nucleotídeos como alternativa aos antibióticos melhores de desempenho. O objetivo deste estudo foi avaliar os efeitos de níveis de nucleotídeos sobre o desempenho, ocorrência de diarreia, peso relativo de órgãos, histologia e microbiota intestinal de leitões recém-desmamados. Cento e sessenta leitões desmamados aos 21 dias (6,43 ± 0,71 kg) foram distribuídos em blocos casualizados com cinco tratamentos, oito repetições por tratamento e quatro animais por baia (unidade experimental). Os tratamentos foram dieta basal com 120 ppm de cloro-hidroxiquinolina (antimicrobiano) e dieta basal com 0 (controle), 100, 150 ou 200 ppm de nucleotídeos. O ganho diário de peso, o consumo diário de ração, a eficiência alimentar e a ocorrência de diarreia foram calculadas nos períodos de 1 a 14, 14 a 34 e 1 a 34 dias de experimentação. Um dia após o final do período experimental, um animal de cada baia foi abatido para avaliar o peso relativo dos órgãos, a histologia e a microbiota intestinal. No período de 1-14 e 14-34 dias, o desempenho dos animais não foi afetado pelos tratamentos. No período total (1-34 dias), com o aumento dos níveis de nucleotídeos na dieta, houve melhora no peso final e no ganho diário de peso. Salmonella spp. foi detectada apenas no tratamento controle, sem afetar os demais micro-organismos. Leitões alimentados com o antimicrobiano apresentaram menor ocorrência de diarreia de 1-14 dias, comparados aos animais suplementados com nucleotídeos. Embora aumente a ocorrência de diarreia no primeiros 14 dias, a inclusão de até 200 ppm de nucleotídeos aumenta o peso final e o ganho diário de peso dos leitões aos 34 dias pós-desmame. Nucleotídeos e antibiótico não mostram efeitos no peso dos órgãos e na histologia intestinal de leitões na fase de creche, entretanto, podem diminuir a população de Salmonella spp. no intestino delgado